From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E48E9C2B9F4 for ; Mon, 28 Jun 2021 11:26:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD16F61220 for ; Mon, 28 Jun 2021 11:26:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232803AbhF1L2u (ORCPT ); Mon, 28 Jun 2021 07:28:50 -0400 Received: from wforward5-smtp.messagingengine.com ([64.147.123.35]:57323 "EHLO wforward5-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232767AbhF1L2u (ORCPT ); Mon, 28 Jun 2021 07:28:50 -0400 Received: from compute1.internal (compute1.nyi.internal [10.202.2.41]) by mailforward.west.internal (Postfix) with ESMTP id BEE471AC016E; Mon, 28 Jun 2021 07:26:23 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute1.internal (MEProxy); Mon, 28 Jun 2021 07:26:24 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=1ACeMP 3IRMAaEM1pRRMRETPZNoRDgcA/Kcp1aH6jhzs=; b=q3mSI7fgJmqeU+20etq5vX wmNEKnIte5tBskKe42CQGeNM0cTXfWeNLHIX3eCPwmewXhIjM/LudWgtb9cKPbt0 WRKqCBy8O39jFLggu7dMPB4yr707cd8ZWvqNdZbNJuvTixo5BAarjQbE8myUoXlX RanTsiLhC/NIlYafZOAafPgLH8o07h7aGcJIk1f6k2G7dKERfbQa3jiCYdic0qtX ClNeGvhwDKNj++9BNJs+czq/XGjDgBAsLZs7xhdjynKIFE1GMokffrTJ1P1yg5qW s3hHDRSfk5Zas2fy8n3jKfPW+9u/hefYY063Fqv7qCXR0z1FQ3ZgkDEm0brLeXFw == X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrfeehgedgfeelucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefuvffhfffkgggtgfesthekredttd dtlfenucfhrhhomhepoehgrhgvghhkhheslhhinhhugihfohhunhgurghtihhonhdrohhr gheqnecuggftrfgrthhtvghrnhepleelledvgeefleeltdetgedugeffgffhudffudduke egfeelgeeigeekjefhleevnecuffhomhgrihhnpehkvghrnhgvlhdrohhrghenucevlhhu shhtvghrufhiiigvpedtnecurfgrrhgrmhepmhgrihhlfhhrohhmpehgrhgvgheskhhroh grhhdrtghomh X-ME-Proxy: Received: by mail.messagingengine.com (Postfix) with ESMTPA; Mon, 28 Jun 2021 07:26:20 -0400 (EDT) Subject: FAILED: patch "[PATCH] mm/memory-failure: use a mutex to avoid memory_failure()" failed to apply to 5.10-stable tree To: tony.luck@intel.com, akpm@linux-foundation.org, bp@alien8.de, bp@suse.de, david@redhat.com, juew@google.com, luto@kernel.org, naoya.horiguchi@nec.com, osalvador@suse.de, stable@vger.kernel.org, torvalds@linux-foundation.org, yaoaili@kingsoft.com Cc: From: Date: Mon, 28 Jun 2021 13:26:18 +0200 Message-ID: <162487957819392@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 171936ddaf97e6f4e1264f4128bb5cf15691339c Mon Sep 17 00:00:00 2001 From: Tony Luck Date: Thu, 24 Jun 2021 18:39:55 -0700 Subject: [PATCH] mm/memory-failure: use a mutex to avoid memory_failure() races Patch series "mm,hwpoison: fix sending SIGBUS for Action Required MCE", v5. I wrote this patchset to materialize what I think is the current allowable solution mentioned by the previous discussion [1]. I simply borrowed Tony's mutex patch and Aili's return code patch, then I queued another one to find error virtual address in the best effort manner. I know that this is not a perfect solution, but should work for some typical case. [1]: https://lore.kernel.org/linux-mm/20210331192540.2141052f@alex-virtual-machine/ This patch (of 2): There can be races when multiple CPUs consume poison from the same page. The first into memory_failure() atomically sets the HWPoison page flag and begins hunting for tasks that map this page. Eventually it invalidates those mappings and may send a SIGBUS to the affected tasks. But while all that work is going on, other CPUs see a "success" return code from memory_failure() and so they believe the error has been handled and continue executing. Fix by wrapping most of the internal parts of memory_failure() in a mutex. [akpm@linux-foundation.org: make mf_mutex local to memory_failure()] Link: https://lkml.kernel.org/r/20210521030156.2612074-1-nao.horiguchi@gmail.com Link: https://lkml.kernel.org/r/20210521030156.2612074-2-nao.horiguchi@gmail.com Signed-off-by: Tony Luck Signed-off-by: Naoya Horiguchi Reviewed-by: Borislav Petkov Reviewed-by: Oscar Salvador Cc: Aili Yao Cc: Andy Lutomirski Cc: Borislav Petkov Cc: David Hildenbrand Cc: Jue Wang Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds diff --git a/mm/memory-failure.c b/mm/memory-failure.c index 0143d32bc666..a7fc1cd6765a 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1429,9 +1429,10 @@ int memory_failure(unsigned long pfn, int flags) struct page *hpage; struct page *orig_head; struct dev_pagemap *pgmap; - int res; + int res = 0; unsigned long page_flags; bool retry = true; + static DEFINE_MUTEX(mf_mutex); if (!sysctl_memory_failure_recovery) panic("Memory failure on page %lx", pfn); @@ -1449,13 +1450,18 @@ int memory_failure(unsigned long pfn, int flags) return -ENXIO; } + mutex_lock(&mf_mutex); + try_again: - if (PageHuge(p)) - return memory_failure_hugetlb(pfn, flags); + if (PageHuge(p)) { + res = memory_failure_hugetlb(pfn, flags); + goto unlock_mutex; + } + if (TestSetPageHWPoison(p)) { pr_err("Memory failure: %#lx: already hardware poisoned\n", pfn); - return 0; + goto unlock_mutex; } orig_head = hpage = compound_head(p); @@ -1488,17 +1494,19 @@ int memory_failure(unsigned long pfn, int flags) res = MF_FAILED; } action_result(pfn, MF_MSG_BUDDY, res); - return res == MF_RECOVERED ? 0 : -EBUSY; + res = res == MF_RECOVERED ? 0 : -EBUSY; } else { action_result(pfn, MF_MSG_KERNEL_HIGH_ORDER, MF_IGNORED); - return -EBUSY; + res = -EBUSY; } + goto unlock_mutex; } if (PageTransHuge(hpage)) { if (try_to_split_thp_page(p, "Memory Failure") < 0) { action_result(pfn, MF_MSG_UNSPLIT_THP, MF_IGNORED); - return -EBUSY; + res = -EBUSY; + goto unlock_mutex; } VM_BUG_ON_PAGE(!page_count(p), p); } @@ -1522,7 +1530,7 @@ int memory_failure(unsigned long pfn, int flags) if (PageCompound(p) && compound_head(p) != orig_head) { action_result(pfn, MF_MSG_DIFFERENT_COMPOUND, MF_IGNORED); res = -EBUSY; - goto out; + goto unlock_page; } /* @@ -1542,14 +1550,14 @@ int memory_failure(unsigned long pfn, int flags) num_poisoned_pages_dec(); unlock_page(p); put_page(p); - return 0; + goto unlock_mutex; } if (hwpoison_filter(p)) { if (TestClearPageHWPoison(p)) num_poisoned_pages_dec(); unlock_page(p); put_page(p); - return 0; + goto unlock_mutex; } /* @@ -1573,7 +1581,7 @@ int memory_failure(unsigned long pfn, int flags) if (!hwpoison_user_mappings(p, pfn, flags, &p)) { action_result(pfn, MF_MSG_UNMAP_FAILED, MF_IGNORED); res = -EBUSY; - goto out; + goto unlock_page; } /* @@ -1582,13 +1590,15 @@ int memory_failure(unsigned long pfn, int flags) if (PageLRU(p) && !PageSwapCache(p) && p->mapping == NULL) { action_result(pfn, MF_MSG_TRUNCATED_LRU, MF_IGNORED); res = -EBUSY; - goto out; + goto unlock_page; } identify_page_state: res = identify_page_state(pfn, p, page_flags); -out: +unlock_page: unlock_page(p); +unlock_mutex: + mutex_unlock(&mf_mutex); return res; } EXPORT_SYMBOL_GPL(memory_failure);